Terminals may be generally classified as mobile/portable terminals or stationary terminals according to their mobility. Mobile terminals may also be classified as handheld terminals or vehicle mounted terminals according to whether or not a user can directly carry the terminal.
As functions of the terminal are getting diversified, the terminal tends to be implemented as a multimedia player with multiple functions of capturing images or videos, playing back music files or video files, gaming, and receiving broadcasting programs, and the like.
Various attempts have been made to implement complicated functions of such a multimedia player by means of hardware or software. For example, a user interface environment is provided to allow users to easily and conveniently search for and select functions.
Also, as a mobile terminal is considered as a personal belonging for expressing his or her own personality, various design forms are requested. The design forms include structural modifications and improvements in order for a user to more easily use the mobile terminal. As one of structural alterations and improvements, a manipulation unit may be considered.
However, the manipulation unit provided separately from a touch screen hinder slim and simple designs of the terminal. In addition, there may be a problem such as reducing a display area due to the manipulation unit disposed at a lateral surface of the mobile terminal. Accordingly, in order to solve such a problem, a manipulation unit with a new structure and an input method thereof may be taken into consideration.
Further, a method for authenticating a user more accurately and securely is also required.